Ch. 13, Development Flashcards
three perspectives on brain development
- structural brain developmnet = predicts behavior
- Behavior = predicts structural brain development
- Other factors are more important: SES, hormones,etc which can all influence brain developmnent
Major findings from research on brain development and SES
Noble 2015 =
1. Lower family income = decreased cortical surface area across frontal, temporal and parietal lobes
2. Worse cognitive perfrormance across language and memory domains
Tower of hanoi, what it tests, profiency ages
tests planning = tests frontal lobe development
age 10: can do very simple forms of this task
age 15-17 can do much more complex versions of the task
Preformation idea in the 1800s
scientists used to believe that sperm and egg cells had tiny humans that just grew up in the womb
reality: embryos look nothing likle adults they become
What supports Darwin’s idea of common ancestry?
that embryos of diff species more closely resemble each other than their parents= supports darwin’s view
Period of zygote, em,bryo, and fetus
Zygote: conception to 2 weeks
embryo: 2 weeks-8 weeks
fetus: 9 weeks–birth
what is the three chambered brain and when is it visibnle in humans?
visible at day 28
includes forebrain, midbrain, hindbrain
Fetal terms for the forebrain, midbrain, and hindbrain
Prosencephalon = will become forebrain
Mesencephalon= will become midbrain
Thombencephalon = will become hindbrain
Mesencephalon + thombencephalon = brainstem
Formation of the neural tube process
- Outermost layer of the embryonic disk becomes thicker
- Forms the neural plate: primitive neural tissue that develops
- = forms the neural tube, a structure in early development from which the brain and spinal cord arise; nursery of cells for the entire CNS
What day is the neural tube developed and what happens if it is defective?
24 days
neural tube = nursery of cells for the entire CNS
if it doesn’t close fully = spinal cord defects
Teratogens and timing
earlier the terotogen = worse timing
“Safest” time to have terotagen: between 6-8 weeks, because migration of the cells hasnt occured yet but b
Anterior vs posterior part of the neural tube
anterior= beomes the spinal cord
posterior = becomes the brain
3 stages of prenatal brain development
- C ell birth (includes neurogenesius and glialgensis)
- Neural migratioin: cells move to specific brain locations
- Differentiation: have to form particular type of cell
4 stages of brain development that occur AFTER BIRTH
- Neural maturation (growth of dendrite and axons)
5., Synaptogensis/forming synapses - Synpatic pruning
- Myelogenosis (formation of myelin) up until age 25-30
ESCs
embryonic stem cells: can become any cell in the embroyo/most unspecialized type
Requirements for a cell to be a stem cell
- Must be able to reproduce itself indefinetly
- Differentiate into more than ONE type of specialized cell
symmetrical vs asymmetrical division of stem cells
symmetrical: one stem cell – produces two stem cells
asymmetrical: one stem cell – produces one stem cell and onew other type of precurser/progenitor cell – which then divides into further cells
4 types of stem cells from most general to most specific
- Totipotent: omnipotent, do everything, most unspecialized, can give rise to embyronic cells and placenta cells, INCLUDES ZYGOTE AND CELLS OF FIRST 2 DIVISIONS
- Pluripotent: can differentiate into all embryonic cells, BUT NOT placenta cells (embryonic stem cells, ESCS)
- Multipotent: can differentiate into multiple specialized cell types found in specific tissues/organs (neural stem cells) but still MULTIPLE TYPES OF CELLS
- Unipotent: single lineage, example: spermatogonial stem cells, can reproduce indefinetly but only as sperm cells
PUMT
Progenitor cell/percursor cell/ neuroblast/glioblast
progenitor/precursor: cell derives from a stem cell that migrates and produced a neuron or glial cell
neuroblast: product of the progenitor cell = then gives rise to diff types of neurons
glioblast: product of a progenitor cell = gives rise to diff types of glial cells
start of neurogensis, differentiation, migration
Neurogenesis 6-25 wks
Migration and Differentiation: 8 - 29 weeks.
Maturation (green bar/green numbers). 20 wks - after birth